Might be interesting for a cheap EMC2 video controller... 700mhz, 256mb ram, runs on an SD card. Not sure about USB support, but a port for smoothstepper would be awesome. Using an LPT port is probably out of the question.
Interesting idea, anyways. At $25 bucks it seems promising.
Writing drivers for the USB end might be interesting. I'd be worried about performance too considering the small ram size. Personally, I think implementing something on an android tablet would be a bit more feasible especially as far as product lifetime/lifecycle is concerned. Food for thought.
That's interesting. I just posted about using this chip for a 3.3V to 5V fix for parallel ports and I did think to apply it to this situation. You can find the mention to it in my comment history somewhere.
As for the reason behind Android, it is a very widely used system and complete open source, so there are plenty of options for development. You would likely have to have the Droid talking to a secondary buffer board that holds lists of time-stamped future 'actions' and executes them according to realtime-clock ticks or a precision oscillator. This buffer-board could just implement a wireless protocall (say bluetooth) to talk to the Droid. Furthermore, the droid OS would allow for graphical control of the machine.
Sorry to disagree but I just don't see this happening for Andriod tablet. Because too difficult to interface hardware.
Also CNC needs real time operating system. There is one for Linux and not such a large step for Rasberry Pi which already is supported by various flavours of linux. EMC2 being the Linux implementaion on x86.
Don't know much about Smoothstepper, but as far as I can see its a USB interface for Mach3 on a Windows PC. Unless they release the SDK for ARM & say Linux I don't see it as any relevance. I would have thought that USB is not the best way to go as there is a delay and lack of direct control. People used Printer ports on PC's because you have direct control of input and output pins. Trouble is what PC has a printer port these days. Given one is trying to drive CNC machines, I would always opt for Real Time Operating system ( i.e. Not windows ) and direct hardware interfacing. Both of which the Raspberry Pi should be able to do with the required developments.
I am also interested in running am embedded RPi EMC2 system, I have some linux background and I am willing to help in any Raspberry Pi Project, I am waiting for a pi to come my way and am thinking about attaching some h-bridges to the gpio. its is all very early days still, but anyone else interested in the project PM me and I'll see if I can start putting some preliminary documentation / designs together.
I don't have much linux knowledge beyond being a user, but I will help wherever possible. It looks like it WILL have to use a smooth stepper, which is an extra cost, but considering the price of the Raspberry Pi it equals out quite nicely when you don't have to shell out a few hundred bucks for a PC. I doubt that a USB parallel port will work fast enough to satisfy the needs of EMC2, but if they could get it working it would be quite nice.
I think the biggest hurdle will be getting smoothstepper drivers to work properly within Linux.
it equals out quite nicely when you don't have to shell out a few hundred bucks for a PC.
Oddly enough an old machine works much much better. I gave up trying to use linuxcnc on a laptop, although an old Pentium 4 desktop works like a charm (I tried a Dell Dimension 3000 motherboard that I had on hand). These can be picked up for next to nothing these days, especially if you know anyone who is upgrading .
But I'd be interested in using a Pi as a controller source too!
Dynomotions k-flop works through USB. It also uses emc2 for g-code. It is a very powerful controller that takes the real time needs off the pc. It might make a good fit for what you are working on. I also don't see why you couldn't get it to work with an android tablet. Just my 2cents.